Perfectly moulded, perfect fit, and accurate not-too-tiny centre hole allowing a clear view. No poroblems.

The first reflector I've owned arrived slightly out of collimation.
Not surprised given the distance it's travelled.
Using this cap, and online tutorials, I've made adjustments to both the primary and secondary mirrors to align them.
Other devices may be quicker, but I've yet to try them.

Great experience with FLO and this collimation cap. As a beginner I was a little hesitant about collimation. But after watching "Small optics " video on YouTube. And using this collimation cap I was impressed how easy it was. Less than five minutes it was done. And super fast delivery thanks to FLO.

If you want a cost-effective, simple and accurate way to collimate your Newtonian telescope, the Rigel Aline Collimation Cap is all you need.

Well made little gadget. The centre peephole was exactly positioned, and the mirrored inside surface makes adjustment easier. I bought this mainly to accurately position the secondary mirror of my Newtonian, then use a Cheshire to complete the collimation adjustments. Secondary mirror adjustment was straight forward, and I was able to see everything clearly through the peephole in spite of wearing spectacles. I then had a go at adjusting the primary mirror, and that was equally straightforward. When I checked it using the Cheshire the collimation appeared more or less spot-on. In many ways I found this collimation cap easier to use than a Cheshire, and certainly worth the money.

Does what it say's, easy to use..an inexpensive option for the purpose.

Quick delivery,had tried laser collimator which was not collimated itself you are far better with the cap I was able to collimate my telescope in no time at all and I'm just a beginner

Simple, cheap and highly accurate.

A great little addition to your collimation toolkit. Just place it in your focuser and check your mirror alignments visually. A good fit in my 1.25” adapter. Sent out and received in 24 hours. Great service

All you need for collimating a Newtonian. Better than using a laser device, some of which are not collimated properly themselves in which case they will never do the job unless you can re-collimate them.

The instructions provided won't be adequate if you are inexperienced, though better instructions are available online, in some books and on u-tube so it shouldn't be a problem.

The cheapest way to accurately collimation your telescope, though it was expecting it to be made from metal rather than plastic. Non the less, it works well and should be all you'll need.